High speed switches, routers and the like are assemblies of electrical circuitry, including printed circuit boards and supporting components such as power supplies and fans to cool the system. Such systems are typically housed in a chassis that in turn is often mounted in an equipment rack.
The printed circuit boards, include input/output (I/O) boards, processing boards and switching boards. Boards within the switch or router connect to other boards within the chassis, directly or indirectly, to allow data transfer therbetween.
To support the ever-increasing speed of communications in networks, interconnection topology incorporating a midplane in place of a typical backplane or series of backplanes, has been devised. Such a topology is described in U.S. Pat. No. 09/483,018, filed Jan. 13, 2000. This matrix switch topology provides a first array of parallel boards on one side of a midplane, a second array or parallel boards on the opposite side of the midplane, with the midplane oriented orthogonally to each array, and each array orthogonal to the other. Boards in both arrays connect to the midplane to allow data and power transfer therebetween.
Typical chassis have a rear panel that can be removed to access components to repair or replace them. With a midplane design, however, this rear access is inconvenient because to access the midplane, all of the components to the rear of the midplane must be removed to access the midplane.
Another issue for chassis design, particularly with a midplane, is providing for convenient connections between components. More specifically, when components are assembled in the chassis during manufacture, it is time-consuming and labor intensive to connect components through wires that must be manually and individually secured. Assembly time is lengthened, and therefore manufacturing cost is increased, since the manual connection of individual wires is slow and allows for errors which, when discovered, require diagnosis of the problem, disassembly, and reassembly, allowing for further connection error. Neatly containing wires and wire harnesses so that they are not in the way of other components is also a problem. Further, maintenance is slow and prone to connection error when individual wirings must be made. It would be desirable to provide snap-together connections such that by positioning a component in its designated, pre-determined position, the proper electrical connections are automatically or easily and quickly made, with little opportunity for error.
Expansion and upgradeability are other issues of concern for chassis for such systems. It would be desirable for a chassis to provide convenient, simple, error-resistant removal and insertion of components for upgrading and expanding the system, such that service can be performed quickly and reliably, with little opportunity for connection error. It would be particularly advantageous for such a system to allow service for repair, expansion, and upgrade while the system remains running.
Chassis design must also provide for efficient, effective cooling of the components inside because they generate heat during operation and will not operate properly or may be damaged if overheated.